1. Field of the Invention
This invention relates to a self-inking stamp for performing an inking upstroke, which stamp comprises a base part, which is adapted to be placed on the surface to be stamped and contains an ink pad, which is opposite to the bottom surface of the base part, a stamp insert, which is disposed in the base part and is adapted to be reciprocated between the ink pad and said bottom surface and to be inverted at the same time and carries a printing plate, and an actuating member, which has two end legs, which extend at opposite ends of the base part and are guided on the outside of the end walls of the base part, which actuating member is displaceable toward the bottom surface against spring force, the ends of a pivot of the stamp insert are movably mounted in said end legs, optionally in slots which extend transversely to the direction in which the actuating member is displaceable, said stamp insert is provided with laterally disposed, longitudinal tracks for receiving respective guide pins, said pivot extends through cam slots, which are formed in the end walls of the base part, which end walls carry the guide pins, or said cam slots are formed in pivoted plates, which are secured to said end walls and carry said guide pins.
2. Description of the Prior Art
Self-inking stamps of that kind, in which the ends of the pivot of the stamp insert are movably mounted in slots, which are formed in the end of said actuating member and extend transversely to the direction in which the actuating member is displaceable, and in which the cam slots cooperating with the pivot of the stamp insert are directly formed in the end walls of the base part, which end walls are also provided with the guide pins, are known, e.g., from Austrian Patent Specification No. 379,552 and the corresponding U.S. Pat. No. 4,603,628. In practice a modification of such self-inking stamps is known, in which the pivot is held in the end legs of the actuating member without a lateral play and extends through the end walls of the base part in a simple longitudinal slot, which extends in the direction in which the actuating member is displaceable. In order to invert the stamp insert during the stamping movement, pivoted plates are secured to the inside of the end walls of the base part and are formed with the cam slots cooperating with the pivot of the stamp inse t and carry the guide pins.
The type on the printing plate is usually so arranged that the letters or numerals or other characters are oriented at right angles to the pivot of the stamp insert so that words or lines of type are parallel to said pivot. But it is often desired to provide a substantial amount of type on the printing plate even though the printing plate should not have an excessive length in the direction of said pivot so that the line length is restricted. In that case it will be necessary to provide a plurality of lines arranged one under the other and the printing plate must have a substantial dimension in the direction which is transverse to the pivot. But it will be appreciated that the stamping stroke, i.e., the displacement of the actuating member between the positions corresponding to the two end positions of the printing plate, will substantially depend on the dimension of the printing plate in the direction which is transverse to the pivot because a pivot for the inversion of a narrow printing plate may be disposed nearer to the ink pad and to the bottom surface than a pivot for the inversion of a wide printing plate, the longitudinal edges of which are spaced a correspondingly larger distance from said pivot. This means that an increase of the width of the printing plate measured transversely to said pivot will result in a considerable increase of the stamping stroke which is required and a stamp comprising a relatively wide printing plate will have a relatively large height and will be unhandy and can hardly be designed for a pleasing appearance.